3. Cast Iron and Commercial Steel Pipe
• Cast iron pipe was frequently used uncoated, although later coatings and linings
reduced corrosion and improved hydraulics. In cast iron pipe, the graphite forms
flakes during the casting process, when examined under a microscope.
• Little cast iron pipe is currently manufactured, since ductile iron pipe is widely
accepted as a superior product. Many public utilities, municipalities, and private
industries still have functional cast iron pipe in service to this day.
• If your building or office is experiencing pipe or drain problems, it is
worthwhile to consider commercial pipe lining. Commercial
pipe lining is a type of pipe lining that does not require digging
trenches or excavations.
4. Fittings Assumptions
• For desired setup, multiple fittings such as elbow and tees are
included in order to have desired flows to respective buildings from
roof storage tanks.
• Pressure loss due these fittings have been successfully included in
friction factor calculation with data available from literature.
• A bend of 180 in normal pipping systems gives us a pressure drop of
0.15 bar.
5. Pipe Elbow
The Elbow is used more than any other pipe fittings. It provides
flexibility to change the pipe direction. Elbow mainly available in two
standard types 90° and 45°. However, it Can be cut to any other degree.
Elbows are available in two radius types, Short radius (1D) and Long
Radius (1.5D).
6. Long radius elbow
In a long radius elbow, the center-line radius is 1.5 times the nominal
size of the pipe or you can say 1.5 times the diameter of the pipe.
Normally long radius elbows are used in piping as pressure loss is less
as compared to short radius elbow. It required more space than a short
radius elbow.
7. Reducing Elbow
The 90 reducing elbow is designed to change direction as well as
reduce the size of the pipe within a piping system. The reducing elbow
eliminates one pipe fitting and reduces the welding by more than one-
third. Also, the gradual reduction in diameter throughout the arc of the
reducing elbow provides lower resistance to flow and reduces the
effect of stream turbulence and potential internal erosion. These
features prevent sizeable pressure drops in the line.
8. Pipe Tee
A pipe tee is used for distributing or collecting the fluid from the run
pipe. It is a short piece of pipe with a 90-degree branch at the center.
There are two types of Tee used in piping, Equal / Straight Tee, and
Reducing / Unequal Tee.
9. Wye Tee / Lateral
It is a type of Tee that has the branch at a 45° angle, or an angle other
than 90°. Wye tee allows one pipe to be joined to another at a 45°
angle. This type of tee reduces friction and turbulence that could
hamper the flow. Wye tee is also known as a lateral.
10. Piping Union
Unions are used as an alternative to flanges connection in low-pressure
small bore piping where the dismantling of the pipe is required more
often. Unions can be a threaded end or socket weld ends. There are
three pieces in a union, a nut, a female end, and a male end. When the
female and male ends are joined, the nuts provide the necessary
pressure to seal the joint.
11. Pipe Nipple
The nipple is a short stub of a pipe that has a male pipe thread at each
end or at one end. It used for connecting two other fittings. Nipples are
used for connecting pipe, hoses, and valves. Pipe nipples are used in
low-pressure piping.
12. Suitable Pump
• For the given task of pumping the said fluid to the desired point a
centrifugal pump is chosen as it is best available option for developing
desired pressure to the desired at height with minimum losses.
• A centrifugal pump has low maintenance cost than the positive
displacement pump.
• Pump characteristics can be changed by changing the design of
impellor with desired operating speed.
13. Amount of Fittings:
First of all the valve at the suction of the pump is applied then at the
discharge of pump a valve. Then for the discharge of fluid into the roof
storage tank two elbows and two non-return valves are used. Then five
tees are used for the supply of each building.
Valves: 2
Non return valve: 2
Elbows:2
Tees:5
14.
15. Materials Selection& Length Assumption
• For the given task we are required to complete it with two different
materials. The materials selected for our calculation are cast iron and
commercial steel pipe due to its easy availability and regular usage.
• The length of pipe assumed for calculation is 120 meter with three
meters apart for each building as provided.
16. Pressure and Head Loss
• The pump pressure, head loss, velocity head, friction factor, relative
roughness, frictional losses in pipe and its impact on developed head
are calculated with three different flow rates for each pipe diameter
for two different materials have been conducted with help of
literature.
• The force required to fix the supply pipe has been calculated through
the usage of assumed density from which required potential energy is
calculated with cylindrical tank volume.
17. Relative Roughness
The relative roughness of a pipe is its roughness divided by its internal
diameter or e/D, and this value is used in the calculation of
the pipe friction factor, which is then used in the Darcy-Weis
Bach equation to calculate the friction loss in a pipe for a flowing fluid.
The shear velocity V* is defined as: V * = τ o / ρ . Darcy friction factor is
a function of the Reynolds number VDH/v and relative roughness ks/DH,
where ks is the equivalent roughness height and DH is the hydraulic
diameter
18. Equations Used
Reynolds Number=- density*velocity*diameter/ viscosity
Fluid Velocity= Flow rate/Cross sectional area
Relative Roughness= Roughness/ Pipe Diameter
Velocity Head= Square of velocity/gravity
Head Loss= Velocity head* miscellaneous losses
Pressure= Density*Head Loss* gravity
Friction Loss=8*friction factor*(Pipe Length/Internal Diamterr)*Density*square of velocity/2
Total Pressure= Pressure+ Friction Losses in pipe
Volume= 2*pi*radius*height*2
Mass= Density*volume
Energy= mass*gravity*height
